Nutritional status and performance in test of verbal and non-verbal intelligence in 6 year old children

Adolescent Cranial Volume as a Sensitive Marker of Parental Investment: The Role of Non-material Resources?

Growth of different body parts in humans is sensitive to different resource constraints that are mediated by parental investment. Parental investment can involve the expenditure of material, cognitive, and emotional resources on offspring. Cranial volume, an important predictor of cognitive ability, appears understudied in this context. We asked (1) whether there are associations between growth and family structure, self-reported estimates for resource availability, and sibling number; and (2) whether these constraints relate to head and body growth in a similar manner. We assessed the associations between parental investment, height, and cranial volume in a cross-sectional study of Estonian children (born 1980-87, aged 11-17). Height correlated negatively with the number of siblings but this association became negligible in a model controlling for birthweight, parental heights, and mother's age at birth. Unlike height, cranial volume was unrelated to sibling number, but it was negatively associated with self-reported meat and general resource shortage. Cranial volume was related to family structure and paternal education. Children living with both birth-parents had larger heads than those living in families containing a step-parent. Since these family types did not differ with respect to meat or general resource shortage, our findings suggest that families including both genetic parents provide non-material benefits that stimulate predominantly cranial growth. For the studied developmental period, cranial volume appeared a more sensitive marker of growth constraints than height. The potential of using cranial volume for quantifying physical impact of non-material parental investment deserves further attention.

Association between intestinal worm infection and malnutrition among rural children aged 9-11 years old in Guizhou Province, China

BACKGROUND

Intestinal worm infection adversely impacted child health and was one of the China's largest health burdens. However, yet little was known about associations between intestinal worm infection and malnutrition in school-aged children in rural China. This study aimed to fill into the gap.

METHODS

Data were from a survey of children aged 9-11 years old in Guizhou Province, China conducted in June 2013. Considering anemia and low intelligent quotient (IQ) as mediating factors, binomial logistic regression was used to estimate the associations of intestinal worm infection with thinness, underweight, and stunting. Moreover, the associations between socio-demographic factors and malnutrition were also explored.

RESULTS

Among 2179 children, part of children was infected by intestinal worm (41.85%). Stunting (28%), low memory IQ (87.52%), and low process IQ (62.59%) were highly prevalent in the sample. Socio-demographic factors were associated with thinness, underweight, stunting, low memory IQ, low process IQ, anaemia, and intestinal worm infection. Intestinal worm infection was associated with low IQ, anemia, and stunting. In addition, anemia and low IQ could not confound the other expected associations.

CONCLUSION

This study demonstrated the association between intestinal worm infections and stunting appeared to be largely mediated via low IQ. The study highlighted the importance of deworming and improving nutrition in the surveyed areas.

Moderately elevated maternal homocysteine at preconception is inversely associated with cognitive performance in children 4 months and 6 years after birth

Prenatal methyl donor deficiency leads to homocysteine accumulation in the brain and impaired neurodevelopment in rats. We investigated the effect of moderately elevated preconception fasting total plasma homocysteine (tHcy) on child neurodevelopment in a prospective study of 67 and 76 mother-child pairs at 4 months and 6 years of age, respectively. Fasting blood samples at 2-10 weeks preconception, from the cord (nonfasting) and the mother and child 6 years after birth, were collected. Psychomotor and mental development were assessed at 4 months using the Bayley Scale of Infant Development (BSID) and cognitive development at 6 years using the Wechsler Preschool and Primary Scale of Intelligence (WPPSI). Highest tertile preconception tHcy (≥9.04 µmol/L) was categorized as moderately elevated and low-mid tertile tHcy as normal. Children, born to mothers with moderately elevated compared to normal preconception tHcy, scored lower [mean (95% CI)] in the BSID psychomotor [115 (105, 124) vs. 126 (121, 130), p = 0.03] and mental [101 (93, 109) vs. 113 (107, 119), p = 0.03] development tests. Multiple logistic regression analysis showed that moderately elevated compared to normal preconception tHcy was associated with greater probability, OR (95%CI), of scoring in the lowest tertile for BSID psychomotor development (≤120): 4.0 (1.1, 14.3) and lowest tertiles for WPPSI full (≤111), verbal (≤104) and performance (≤111), intellectual quotient: 6.0 (1.5, 23.7), 3.5 (1.1, 11.2) and 4.1 (1.1, 15.7), respectively. We conclude that moderately elevated preconception tHcy is inversely associated with psychomotor and cognitive development scores in infants and children.

Physical growth and nonverbal intelligence: associations in Zambia

OBJECTIVE

To investigate normative developmental body mass index (BMI) trajectories and associations of physical growth indicators--height, weight, head circumference (HC), and BMI--with nonverbal intelligence in an understudied population of children from sub-Saharan Africa.

STUDY DESIGN

A sample of 3981 students (50.8% male), grades 3-7, with a mean age of 12.75 years was recruited from 34 rural Zambian schools. Children with low scores on vision and hearing screenings were excluded. Height, weight, and HC were measured, and nonverbal intelligence was assessed using the Universal Nonverbal Intelligence Test, Symbolic Memory subtest and Kaufman Assessment Battery for Children, Second Edition, Triangles subtest.

RESULTS

Students in higher grades had a higher BMI over and above the effect of age. Girls had a marginally higher BMI, although that for both boys and girls was approximately 1 SD below the international Centers for Disease Control and Prevention and World Health Organization norms. When controlling for the effect of age, nonverbal intelligence showed small but significant positive relationships with HC (r = 0.17) and BMI (r = 0.11). HC and BMI accounted for 1.9% of the variance in nonverbal intelligence, over and above the contribution of grade and sex.

CONCLUSION

BMI-for-age growth curves of Zambian children follow observed worldwide developmental trajectories. The positive relationships between BMI and intelligence underscore the importance of providing adequate nutritional and physical growth opportunities for children worldwide and in sub-Saharan Africa in particular. Directions for future studies are discussed with regard to maximizing the cognitive potential of all rural African children.

Three-month B vitamin supplementation in pre-school children affects folate status and homocysteine, but not cognitive performance

BACKGROUND

Suboptimal vitamin B status might affect cognitive performance in early childhood. We tested the hypothesis that short-term supplementation with folic acid and selected B vitamins improves cognitive function in healthy children in a population with relatively low folate status.

METHODS

We screened 1,002 kindergarten children for suboptimal folate status by assessing the total urinary para-aminobenzoylglutamate excretion. Two hundred and fifty low ranking subjects were recruited into a double blind, randomized, controlled trial to receive daily a sachet containing 220 μg folic acid, 1.1 mg vitamin B2, 0.73 mg B6, 1.2 μg B12 and 130 mg calcium, or calcium only for 3 months. Primary outcomes were changes in verbal IQ, short-term memory and processing speed between baseline and study end. Secondary outcomes were urinary markers of folate and vitamin B12 status, acetyl-para-aminobenzoylglutamate and methylmalonic acid, respectively, and, in a subgroup of 120 participants, blood folate and plasma homocysteine.

RESULTS

Pre- and post-intervention cognitive measurements were completed by 115 children in the intervention and 122 in the control group. Compared to control, median blood folate increased by about 50% (P for difference, P < 0.0001). Homocysteine decreased by 1.1 μmol/L compared to baseline, no change was seen in the control group (P for difference P < 0.0001) and acetyl-para-aminobenzoylglutamate was 4 nmol/mmol higher compared to control at the end of the intervention (P < 0.0001). We found no relevant differences between the groups for the cognitive measures.

CONCLUSION

Short-term improvement of folate and homocysteine status in healthy children does not appear to affect cognitive performance.

Dietary patterns in infancy and cognitive and neuropsychological function in childhood

BACKGROUND

Trials in developing countries suggest that improving young children's diet may benefit cognitive development. Whether dietary composition influences young children's cognition in developed countries is unclear. Although many studies have examined the relation between type of milk received in infancy and subsequent cognition, there has been no investigation of the possible effect of variations in the weaning diet.

METHODS

We studied 241 children aged 4 years, whose diet had been assessed at age 6 and 12 months. We measured IQ with the Wechsler Pre-School and Primary Scale of Intelligence, visual attention, visuomotor precision, sentence repetition and verbal fluency with the Developmental Neuropsychological Assessment (NEPSY), and visual form-constancy with the Test of Visual Perceptual Skills.

RESULTS

In sex-adjusted analyses, children whose diet in infancy was characterised by high consumption of fruit, vegetables and home-prepared foods ('infant guidelines' dietary pattern) had higher full-scale and verbal IQ and better memory performance at age 4 years. Further adjustment for maternal education, intelligence, social class, quality of the home environment and other potential confounding factors attenuated these associations but the relations between higher 'infant guidelines' diet score and full-scale and verbal IQ remained significant. For a standard deviation increase in 'infant guidelines' diet score at 6 or 12 months full-scale IQ rose by .18 (95% CI .04 to .31) of a standard deviation. For a standard deviation increase in 'infant guidelines' diet score at 6 months verbal IQ rose by .14 (.01 to .27) of a standard deviation. There were no associations between dietary patterns in infancy and 4-year performance on the other tests.

CONCLUSIONS

These findings suggest that dietary patterns in early life may have some effect on cognitive development. It is also possible that they reflect the influence of unmeasured confounding factors.